B,
Here's my thoughts and listening experiences with my Nott set up which is similiar to yours minus the OL-1. Found the Dynavector and Clearaudio cartridge had best synergy with the Rega based arms. Personally, if your budget can afford, I suggest either the Dynavector 20X (retail $525) high output or the Clearaudio Virtuoso Wood(retail $750). The later is a moving magnet design with 3.6mV output.
I heard the Benz ACE HO on an Interspace turntable and tonearm set-up at a highly regarded Nott dealer, thought is sounded like sh_t. Either the cartridge was misaligned or something was off.
I personally got the Dynavector 10X4mkII and think it sounds great. With the OL-1 arm, suggest you stretch your budget on the cartridge. If you haven't set one up, make sure a good analog dealer or experienced friend is there to help. Keep reading posts on Vinyl Asylum about someone who has messed things up.
Please PM me if you wish to discuss further.
Regards,
NB